Transition-metal triflate catalyzed unprecedented formation of oxime ketals of tetrahydrofuran via C–H functionalization

• Rare earth metal triflate catalyzed C–H activation of THF.
• Unprecedented formation of oxime ketals of tetrahydrofuran.
• C–O bond formation through C–H activation.
• Product confirmation through 2D NMR techniques.

Benzaldehyde O-tetrahydrofuran-2-yl oximes were formed through the C–H functionalization from the reaction between benzaldoximes and aqueous tetrahydrofuran catalyzed by water tolerant transition metal triflates (Lewis acids). The formation of oxime ketal has been confirmed from 2D NMR analysis (HMBC and HSQC studies).